The present invention is generally directed to a pallet and, more specifically, a modular pallet.
Pallets have been widely utilized in environments, such as, warehouses and factories, to provide a portable platform for handling, storing and moving materials. A typical pallet includes multiple spaced top slats mounted to a top surface of multiple spaced transverse support elements, which elevate the top slats from the ground and allow handling of the pallet with equipment, such as a forklift. Multiple bottom slats are also typically mounted to a bottom surface of the support elements to provide additional structural support for the pallet.
In general, weight, cost, structural strain, versatility of use, ease of transportation and ability to reuse the materials of the pallet are important factors in evaluating a pallet construction for an application. Historically, pallets have been constructed of wood. Recently, however, a number of plastic modular pallets have been suggested and/or introduced. The components for a plastic pallet may be injection molded, extruded or rotationally molded and may be made of various materials, such as polyethylene, polypropylene, polystyrene and polyvinyl chloride. U.S. Pat. No. 3,878,796 discloses a plastic pallet assembly that includes spaced longitudinal stringers with spaced boards attached to and extending transversely of the stringers. The stringers and boards include an arrangement of integral notches and shoulders and are interconnected by driving the components together. However, the plastic pallets disclosed in U.S. Pat. No. 3,878,796, are not constructed to prevent the boards from shifting in a direction transverse to the longitudinal stringers.
U.S. Pat. No. 5,101,737 discloses a pallet that includes spaced foundation rails having planar top and bottom walls with orthogonally oriented grooves arranged parallel to and extending co-extensively of each of the rails. A number of spaced bottom and top strips are provided that include leg pairs that are received by the grooves in the foundation rails such that a snap-fit inter-relationship is achieved between the foundation rails and the strips. The strips are connected to the foundation rails with gel packets that include epoxy resin and epoxy hardener, which mix during assembly and thereby permanently affix the strips to the foundation rails.
U.S. Pat. No. 5,440,998 discloses a plastic pallet that includes a number of spaced stringer members with integral fastening studs. Spaced longitudinal deck board members, which include apertures for receiving the fastening studs, are placed transversely to the stringer members at which point the studs are heated to affix the deck board members to the stringer members. In another embodiment, screws are utilized to attach the deck board members to the stringer members. It should be appreciated that removing a damaged deck board member from a transverse stringer member either requires heating of the studs or requires removal of screws depending upon the embodiment.
U.S. Pat. No. 5,458,069 discloses a plastic pallet that includes a number of spaced rails with integral posts and spaced cross members, which include apertures to receive the posts. The spaced rails are attached to the cross members by ultrasonically welding the posts to the cross members. In an alternative embodiment, the posts are threaded to receive a nut which, when in place, attaches the cross members to the rails.
U.S. Pat. No. 5,941,179 discloses a modular pallet that includes a number of spaced runners having transverse clasping slots and a number of spaced slats including longitudinal fastening ridges that are shaped to mate in releasable connection with the clasping slots in the runners. While the pallets described above are modular, the pallets described above do not generally provide a pallet that is readily assembled/disassembled and economically competitive.
What is needed is an improved modular pallet that is relatively low in cost, when compared to other commercially available modular pallets. It would also be desirable for the modular pallet to include components that readily interconnect in a reliable, efficient manner and which maintain the interconnection under normal use and are capable of being readily disassembled.